In a mixer, add the two flours, the sugar, the yeast, the lemon zest and mix. Then add the egg, the water and finally the milk. You must obtain a compact dough.
Now let’s move onto a floured cutting board and knead until you obtain a smooth dough. Leave to rise covered with a film or a cloth for 4/5 hours.
After the leavening time, spread the dough on a pastry board with a rolling pin and the thickness must be 1 cm. Cut the dough with a cup or a pastry cutter. Leave to rise for 20 minutes covered by a cloth.
Prepare the oil for frying in a saucepan, let it warm up and when it is ready put a mini donut at a time and let it cook until it becomes brown, (about 20 seconds per side).